Fuel vaporization and injection system for internal combustion engine

#The present invention pertains to internal combustion engines, and more particularly to a new and unique fuel injection system in which liquid hydrocarbon fuel is converted into high-temperature, high-pressure vapor, which is then injected into the combustion chamber at the peak of the compression stage, where it mixes with air and ignites for the power stroke.

#Heretofore, virtually all internal combustion engines using liquid hydrocarbon fuel, such as gasoline or diesel oil, have utilized carburetors or fuel injectors to deliver the liquid fuel into the intake air, or into the combustion chamber, in the form of finely atomized mist, which is supposed to evaporate completely, with the result that some of the fuel is still in liquid form during the combustion stage, and because of this it burns incompletely, leaving a considerable amount of unburned fuel in the exhaust to pollute the atmosphere. This unburned fuel in the exhaust also means reduced efficiency, lower power output, and poor fuel consumption characteristics. Moreover, the heat of vaporization which goes into evaporating the fuel in the intake manifold or the combustion chamber is subtracted from the total heat of combustion, with the result that the heat available for expansion on the power stroke is decreased, with a corresponding reduction in power output and efficiency.

#In the case of gasoline engines (e.g., Otto cycle), the compression ratio is limited to a maximum value of about 12 to 1, unless exotic fuels of extremely high octane rating are used, as detonation becomes a serious problem.

#FIG. 1 is a schematic sectional view through one cylinder of an engine of the 4-stroke cycle type, embodying the principles of the invention;

#FIG. 2 is an enlarged fragmentary sectional view taken at 2--2 in FIG. 1;

#FIG. 3 shows schematically the 4 cycles of operation;

#In the drawings, the internal combustion engine embodying the invention is designated in its entirety by the reference numeral 10, of which the upper portion only of the cylinder 12, piston 14, and associated parts are shown in FIG. 1. The illustrative engine 10 is a 4-stroke cycle, piston-type gasoline engine, but the invention is not limited to this type of engine, and is equally applicable to a 2-stroke cycle rotary (e.g., Wankel engine), and diesel engines.

#Piston 14 slides vertically within the cylinder 12, and is connected by a connecting rod 16 to the crankshaft (not shown). Air (or a mixture of air and carbureted gasoline warm-up) is drawn into the combustion chamber 18 through intake manifold 20, controlled by intake valve 22; while the exhaust gas is discharged through an exhaust manifold 24, controlled by an exhaust valve 26. A conventional sparkplug 28 screwed into the cylinder head and connected to the usual distributor (not shown), ignites the charge when the engine is operating as a conventional gasoline engine during starting and warm-up, as will be described in more detail presently. A carburetor 30 is connected to the intake manifold 20, and has the usual venturi 31, fuel jet 32, float chamber 33, and throttle valve 35. The float chamber 33 is supplied with gasoline by a fuel line 36, having a cut-off valve 38 actuated by a solenoid 40.

#The engine described to this point (with the exception of solenoid valve 38, 40) is essentially a conventional 4-stroke cycle gasoline engine, and operates as such during starting and warm-up. After warm-up has been completed, the engine is switched over to a different mode of operation involving fuel vaporization and injection, and it is with this new mode of operation that the present invention is concerned.